The present invention relates to knife opener which may be used as part of no-till or minimum-till farming practices primarily for placement in the ground of seed and/or fertilizer and other materials.
Important advantages have been found in soil preparation, and seed and fertilizer delivery in employing no-tilling or minimum tilling methods which cause minimum disturbance to the soil. This is particularly important in drier soil conditions where the soil is subject to moisture and topsoil loss if conventional tilling methods are used. It is usually desirable when employing no-till farming practices to disturb the soil surface as little as possible. The surface will be covered with the residue from previous crops, and the surface layer will contain old root structure. This plant material can serve to retain moisture below the surface and to assist in securing the soil against runoff and erosion.
Fertilizer is commonly used to improve crop yields. Broadcasting the fertilizer on the surface is a method that does not disturb the surface, but it can be inefficient as much of the fertilizer can be lost due to runoff surface water. As such, a number of soil bed preparation tools have been developed that are designed to place fertilizer directly in the soil. An example of such a device is a double shoot air drill which enables seed and fertilizer to be deposited as a knife, coulter or other device is towed through the soil.
Zero till or minimum till devices have been developed to deposit high concentrations of fertilizer in the furrows formed by the knife or other furrowing tool. If the seed is placed in close proximity to a high concentration of fertilizer, burning of the newly germinated plant can result. Thus, with higher fertilizer concentrations, it is generally desired to space the fertilizer from the seed, either laterally and/or vertically.
As noted above, one type of furrow opening tool is a knife. To achieve adequate separation either vertically or horizontally with a knife has required the knife to occupy a relatively large amount of space either in the soil or above the soil. In the case of the former, the knife opens a relatively large furrow thereby resulting in greater soil disturbance. In the case of the latter, the flow of residue around the knife can be impeded.
If the flow of residue is impeded that residue tends to collect around the knife and is dragged with the knife as the implement is towed. Not only can this residue collection impair operation of the implement, it also removes the desired moisture retaining cover that may be provided by the residue.
Another type of furrowing device is a coulter or disk opener. While disk openers have the ability to cut through most residue, some crop residue, such as straw, may not cut easily, and as a result may be pushed into the furrow, a result commonly called hair-pinning. This can displace seeds, as well as drying out the seed bed. Additionally, effective no-till disc openers can be quite costly.
Thus, there remains a need for a knife opener that cuts a furrow with reduced soil disturbance yet provides the desired spacing for higher concentrations of fertilizer. There is also a need for such a knife opener which provides tilling and/or seeding, fertilizing, or weed clearing in a single pass without significant trash accumulation.